Lighting device

ABSTRACT

The invention concerns an energy saving electrical system with good energy economy for the ignition, operation and extinguishing of gas-discharge lamps, such as up to four low-pressure fluorescent lamps or the equivalent, high-pressure mercury lamps and both high-pressure and low-pressure lamps of sodium type or metal halogen lamps in alternating current networks. The system comprises a rectifier ( 1 ), a capacitor ( 2 ), a power transistor ( 50 ) and a first transformer and a second transformer (T 1 , T 2 ), each with several windings. The system furthermore comprises means ( 46 ) for stabilising the emission of light during changes of voltage in the supply network, and means ( 59, 39, 3, 46, 19, 35, 52 ) for limiting the current through and the voltage across the power transistor ( 50 ). Lamps that are to be used are connected to outputs of the windings ( 98 107 ), which windings are designed and connected such that they cooperate in order to operate the relevant lamp or lamps with negative and positive currents that are equal in magnitude.

TECHNICAL FIELD

The invention concerns electrical technology, namely an energy savingelectrical system for the ignition, operation and extinguishing ofgas-discharge lamps such as low-pressure fluorescent lamps,high-pressure mercury lamps and both high-pressure and low-pressurelamps of sodium type or metal halogen lamps in alternating currentnetworks.

THE PRIOR ART

A operational circuit for a light source is known through U.S. Pat. No.5,130,609, filed 26 Jan. 1990, published 17 Jul. 1992, which operationcircuit comprises an input transformer that is connected via a rectifierbridge and a diode to a smoothing capacitor. The collector of atransistor is connected to the positive electrode of the smoothingcapacitor via a potentiometer and the first winding of the transformer.The base contact of the transistor is connected to the positiveelectrode of the smoothing capacitor via the second winding of thetransformer. The negative electrode of the smoothing capacitor isconnected to the emitter of the transistor and, via a capacitor, to thefirst winding of the transformer. The third winding of the transformeris connected to a fluorescent lamp.

A rectified voltage from the supply network and the smoothing capacitoris delivered in this operation circuit via the potentiometer to thewinding of the transformer, and passes via the second winding to thebase of the transistor. Positive feedback is created in this way and thecircuit is activated. Rectangular voltage pulses are created at thecollector of the transistor that are transformed by the third winding ofthe transformer and pass to the lamp.

The current that passes through the lamp is small when the lamp does notgive a light, the voltage impulses are large and ignite the lamp. Thecurrent increases, the voltage of the impulses decreases to a value thatis sufficient for gas combustion in the lamp.

Disadvantages of the device are that it can only be used for lamps oflow power since the current that passes through the potentiometer andthat feeds the complete circuit increases when the power is increased.Power losses increase and the potentiometer becomes overheated.Furthermore, the negative voltage impulse at the lamp has a constantvalue that is proportional to the supply voltage and the positivevoltage impulse has an alternating value that depends on the resistanceof the lamp. As a result of this, the value of the negative current ofthe lamp is not equal to the positive current of the lamp, and the lampgives an unstable illumination, and may become extinguished at one ofits ends. In addition, the transistor has no protection against voltageoverload at the instant at which the lamp is ignited, since the voltageis not limited to the value that is required to pass through the gas inthe lamp if the lamp is broken, and the voltage increases and destroysthe transistor.

The device also lacks a limitation of the current when the potentiometeris closed.

The device cannot be used for two or more lamps.

A lighting system is known through the UK patent application number 2047 486, filed 12 Apr. 1979, published 26 Nov. 1980, which systemcomprises a supply network filter that is connected to a smoothingcapacitor via a rectifier. The positive electrode of the smoothingcapacitor is connected via a relay to a first winding of a transformer,via a first potentiometer and a first resistor to the base of atransistor, which is connected via the capacitor, a second resistor, asecond potentiometer and a second winding of the transformer to thenegative electrode of the smoothing capacitor and to the emitter of thetransistor. The collector of the transistor is connected to a secondoutput from the first winding of the transformer. A third winding of thetransformer is connected to a lamp; the winding of the relay isconnected to the output of a transistor amplifier. The input of thetransistor amplifier is connected to a first photoresistor, the firstphotoresistor is connected in parallel with a second photoresistor thatis illuminated by a light unit that is connected to a part of the thirdwinding of the transformer or that is illuminated by an external light.The second resistor is connected in parallel to a third photoresistorthat is illuminated by a photodiode.

In this system, the rectified supply voltage comes from the smoothingcapacitor to the first winding of the transformer and passes via thefirst resistor and the first potentiometer to the base of thetransistor. The second winding of the transformer creates a positivefeedback, the system is activated and rectangular voltage pulses arecreated at the collector of the transistor. These impulses pass via thefirst winding to the third winding of the transformer and subsequentlyto the electrodes of the lamp. The lamp has a high inner resistance whenit does not give a light, the impulses inside the lamp reach thebreakthrough value, the lamp starts to light, its resistance decreasesand lower voltage impulses are created in the lamp that ensure theemission of light. The potentiometer regulates the current at the baseof the transistor and at the same time the intensity of light from thelamp. A first photoresistor, if external illumination is present,disconnects supply for the generator circuit via a relay and the lamp isextinguished. In the absence of external illumination, the lamp isignited by the first photoresistor. The second and third photoresistorsare connected in shunt to the first and second resistors. In this waythey alter the current at the base of the transistor and regulate theintensity of illumination of the lamp depending on the externalillumination by altering the voltage in the third winding.

Disadvantages of such a system are that it is not possible to use itwith two or more luminescent lamps, with high-pressure lamps that have ahigh ignition voltage or with metal halogen lamps. Furthermore, thecurrent in the lamp has different values for the positive and thenegative amplitudes since the first half-wave of the voltage has anamplitude that is proportional to the voltage of the supply network, andthe second half-wave of the voltage is equal to the operating voltage ofthe lamp, and these two voltages are not equal to each other. Thus thelight emission of the lamp will be uneven along the length of the lampand one of its ends will become extinguished after a period. Inaddition, limitation of the current strength in the transistor islacking which, when the lamp is broken, may lead to the transistorbecoming destroyed. Furthermore, protection against overheating islacking. Furthermore, there is no voltage protection for the transistorif the lamp is not connected in the circuit.

The strength of illumination is regulated by changing the current in thebase of the transistor, which leads to a lamp, which does not give astable light, since the amplification coefficient for the base currentin the transistor depends on its temperature. Use of a relay forignition and extinguishing of the lamp is therefore unreliable since thecapacity of the relay is limited by its design.

Regulation of the intensity of illumination by the first resistor is notefficient with regard to saving energy due to the large reduction involtage (up to 300 volts) across it, and due to the reduction of theresistance of the resistor leading to power losses and overheating ofthe resistor.

A high-frequency power source for luminescent lamps is known throughU.S. Pat. No. 4,005,335, filed 15 Jul. 1975, published 25 Jan. 1977. Thedevice comprises a rectifying diode bridge, the two inputs of which areconnected to an alternating current network and the two outputs of whichare connected to electrodes of a first capacitor. The positive output ofthe rectifier is connected via a first winding of the transformer to thecollector of a transistor and to the cathode of a first diode. The anodeof the diode is connected to the negative output of the rectifier, tothe emitter of the transistor, to the electrode of a second capacitor,with outputs of second, third and fourth windings of the transformer andvia two luminescent lamps connected in parallel and a third capacitorwith a second output at a fourth winding of the transformer, in parallelwith a fourth capacitor, a second output of a second winding isconnected in parallel via a fifth capacitor to the circuit thatcomprises a first resistor, a first potentiometer and a second diode allconnected in series and connected to the base of the transistor, whichis connected via a second resistor to the positive output of therectifier and via a zener diode (a stabilitron) to a second electrode ofa second capacitor and via a third diode with a second output of a thirdwinding of the transformer. A second potentiometer is connected betweenthe base of the transistor and the negative output of the rectifier.

When the supply voltage arrives, a direct voltage of approximately 280 Vis created at the output of the rectifier that passes to the circuit ofthe autogenerator that is arranged with a transistor and a transformer.The second winding of the transformer creates a positive feedback.Rectangular pulses are created at a fourth winding of the transformerand pass via a third capacitor to electrodes of two lamps.

The inner resistances of the lamps are initially high, the amplitude ofthe impulse voltage increase and reaches a breakthrough value for twolamps. The lamps are ignited. The voltage amplitude in the lampsdecreases to the operating voltage that maintains the lamps luminous.Similar processes occur for the voltage at the third winding with theexception that the voltage value is reduced by several times thetransformation coefficient (approximately 100 times).

When the current in the network is switched on by this system althoughthe lamps do not light, a negative impulse amplitude of approximately 11volts exists, which charges via a third diode a second capacitor to avoltage of −10.3 volts. In this way, the stabilising voltage of 12.4volts does not pass through the zener diode and the zener diode does notaffect the function of the circuit. If one of the lamps has broken, thevoltage in the lamps exceeds the value of the ignition voltage, theamplitude of the impulse at the collector of the transistor increases,the voltage at the second capacitor increases, and the zener diode openswhen the voltage reaches 12.4 volts. In this way, the voltage at thebase of the transistor decreases, the increase of the amplitude of theimpulse at the collector of the transistor ceases and this ensures thatthe transistor is not destroyed.

A first potentiometer regulates the feedback current from a secondwinding to the base of the transistor which ensures alterations in thestrength of illumination. A second potentiometer reduces the feedbackcurrent by short-circuiting it past the base to a general conductor. Inthis way, the intensity of illumination of the lamps is also regulated.An overall regulation of the intensity of illumination of ±40% ispossible.

Disadvantages of this high-frequency power source are that it is notpossible to use it for four luminescent lamps, for high-pressure lampsor for metal halogen lamps whose value of ignition voltage reaches 4kilovolts. Furthermore, the alternating current in the lamp hasdifferent positive and negative amplitudes since the first half-wave ofthe voltage impulse in the lamp has an amplitude that is proportional tothe voltage in the network and this is constant. The second half-wave ofthe voltage is equal to the operating voltage of the lamp and thesevoltages are not equal. Thus the rectified part of the current in thelamp passes only in one direction, the lamp gives an unevenly lightalong the length of the lamp, and one of the ends of the lamp becomesextinguished after a period.

Protection of the transistor against uncontrolled increase of thecurrent that passes through it is also lacking in this system.Regulation of the intensity of the illumination takes place by changingthe base current of the transistor, which leads to the lamp notproviding stable illumination since the amplification coefficient forthe base current of a transistor depends directly on its heatingtemperature.

Furthermore, the transistor in the system is not protected againstoverheating in an extreme working environment, and it may becomedestroyed. Furthermore, stabilisation of the intensity of illuminationof the lamp when the voltage in the supply network changes is lacking,as it is when older lamps are used. Automatic systems for the ignitionand extinguishing of lamps depending on time, on external illuminationand on the presence of people in the vicinity of the lamps are alsolacking.

DESCRIPTION OF THE INVENTION

The aim of the present invention is to ensure a possibility of using asystem to ignite simultaneously high-pressure mercury lamps orluminescent lamps in a quantity of from one to four, or up to fourlow-pressure lamps of the sodium vapour type, or with a high-pressurelamp with a higher ignition voltage, or with a metal halogen lamp; toensure a protection for the transistor against overload by current andagainst overheating; to ensure stabilisation of the intensity ofillumination of the lamp during changes of voltage in the supply networkand over time; to ensure a stable regulation of the intensity ofillumination of the lamp to a higher degree and to ensure automaticignition and extinguishing of the lamps depending on externalillumination, time and the presence of people.

The above-mentioned aims are achieved with the system for ignition,operation and extinguishing of connected gas-discharge lamps, whichsystem is intended for different types of lamp and comprises arectifier, a capacitor, a power transistor, and a transformer with atleast four windings. Characteristics for the system, according to theinvention are given in the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The system according to the invention is illustrated in the drawings, ofwhich

FIG. 1 shows a circuit diagram for the illumination system according tothe invention and

FIG. 2 shows timing diagrams.

EMBODIMENTS OF THE INVENTION

As is shown in FIG. 1, the system comprises a rectifier 1, capacitors2-14, resistors 15-34, potentiometers 35, 36, 37, thermoresistor 38,diodes 39-45, zener diodes 46, 47, 48, light diode 49, power transistor50, transistors 51-55, phototransistors 56, 57, 58, windings of the,first transformer 59-64, windings of the second transformer 65-70,generator 71, field effect transistor 72, lamps 73-81, amplifiers 82-86,microphone 87, amplitude detectors 88-90, capacitance electrode 91,Schmitt trigger j92, frequency detector 93, accumulator 94, timer 95,multiplier 96, diode 97, contacts at the first transformer 98-101,contacts at the second transformer 102-107, output contacts of thesystem 108-112, and diode 113.

The alternating supply network with a voltage of 22 volts is connectedvia rectifier 1 to the capacitor 2; the positive output of the rectifieris connected to the contact 98 of the winding 61 of the firsttransformer T1 and via the resistor 15 to the base of the powertransistor 50, to the cathode of the zener diode 46, to the electrode ofthe resistor 16, to the electrode of the resistor 17, to the electrodeof the capacitor 4, to the collectors of the transistors 51, 52. Theiremitters are connected to the negative output of the rectifier 1, tocontacts at the windings 59, 60 and 64, to electrodes at the capacitors3 and 5, to the resistors 18, 35, 19, to the electrode of the capacitor6, to the anode of the diode 97, with the general output from thegenerator 71, with the source electrode of the field effect transistor72, the gate of which is connected to the output of the generator 71.

The supply output of the generator 71 is in turn connected to a secondelectrode of the capacitor 5, to the collector of the phototransistor 56and to the cathode of the diode 42, the anode of which is connected tothe second electrode of the capacitor 4, to the cathode of the diode 41,to the second contact of the winding 60 and to the anode of the diode40, the cathode of which is connected to the second electrode of theresistor 16, and the anode of the diode 41 is connected to the secondelectrode of the resistor 17. The second contact of the winding 59 isconnected to the cathode of the diode 39, the anode of which isconnected to the anode of zener diode 46 and to the second electrode ofthe capacitor 3. The emitter of the phototransistor 56 is connected tothe second electrode of the resistor 18 and to the base of thetransistor 51, and the base of the transistor 52 is connected to theregulator of the potentiometer 35, the second electrode of which isconnected to the second electrode of the resistor 19 and to the emitterof the power transistor 50, the collector of which is connected to thecontact 100 on the winding 63 and via winding 62 to the contact 99 onthe winding 61. The winding 64 is connected with the second contact tothe anode of the diode 113, the cathode of which is connected to thesecond electrode of the capacitor 6, to the winding 66 of the secondtransformer and connected via the winding 65 of the second transformerto the drain output of the field effect transistor 72, and to thewindings 69 and 70 of the second transformer, which windings areconnected in series. The cathode of the diode 97 is connected to thesecond contact of the winding 66 and via the winding 67 to the contact105 of the winding 68. The lamp 73 is connected to contacts 102 and 103of the winding 65.

The device functions in the following manner. The network voltage, 220V, 50 Hz, is applied at the input of the rectifier 1. A direct voltage Eof approximately 280 volts is obtained at the output of the rectifier.The capacitor 2 smoothes pulses in this voltage. The direct voltage Ethen is applied at feed circuits of a pulse oscillator that consists ofthe power transistor 50 and the transformer T1 with the windings 59-63.An initial current arrives at the base of the transistor 50 through theresistor 15, which current opens the transistor 50 and activates theoscillator. This then creates impulse oscillations with a frequency ofapproximately 30 Hz. When the transistor 50 is open, a positive voltagepulse Um4 of approximately 10 volts arises at the winding 60, which ispresent to create a positive feedback, and this voltage creates acurrent in the base of the transistor 50 via the diode 40 and theresistor 16. The voltage at the collector is equal to 0 V. Thus a directvoltage E is present at the windings 61 and 62, and the current throughthe windings 61 and 62 and through the transistor 50 increases accordingto the equation:I50=(E/L)*t, where L is the inductance in the windings 61, 62.

Subsequent to the current I50 reaching the value β50*Ib, where β50 isthe amplification coefficient of the transistor for the current, thetransistor 50 is closed, its collector voltage U100 increases and thevoltage at the winding 60, U60, decreases and becomes negative, closingthe transistor 50 via the diode 41 and the resistor 17. The negativevoltage in the winding 60, Um3, can reach high values. This is why theresistance of the resistor 17 is 10 times larger than the resistance ofthe resistor 16. Thus, only a small current emerges from the winding 60,something that contributes to saving energy. Energy is saved in thewindings 61, 62 when the transistor 50 is closed:Wi=(L*Im ²)/2, where Im is the maximum value of the current I50.

A high-frequency voltage impulse Um1 is created at the collector of thetransistor 50.

This must not exceed the breakthrough voltage of the transistor ofapproximately 1500 V. The. collector voltage Um1 of the transistor islimited to a level of 880 V with the aid of the winding 59 in order toprevent breakthrough. At Um1=880 V, a negative voltage of approximately6.2 V is created that charges the capacitor 3 to a direct voltage of 5.6V via the diode 39, which voltage is equal to the stabilisation voltageof the zener diode 46. When the transistor 50 again opens, the zenerdiode 46 transmits a part of the current from the resistor 16 and inthis way reduces the base current in the transistor 50 to the value Im1,which limits is the increase of the collector impulse by the voltageUm1.

The positive voltage impulses Um4 in the winding 60 charge via the diode42 the capacitor 5 to a constant voltage of 9.4 V, which voltage is usedto feed other units of the device that must be fed with low voltage.Energy is in this way saved since the feed of these units from a sourcewith E=280 V would require more energy in reducing resistors. Thevoltage at capacitor 5, U108, is sufficiently stable; it is changedproportionally with the voltage in the feed network, which normally mustlie within ±10%. The power of the stable voltage is explained by thefact that the amplitudes of the alternating voltages of the samepolarity at all winding 59-63 depend on the resistance in the load ofthe generator, and the amplitudes of the voltages of the oppositepolarity are proportional to the voltage in the network that is used tocharge the capacitor 5.

The number of turns in the windings 61 and 62 is equal to the number ofturns in the winding 64, and thus a voltage impulse on winding 64 iscreated that is equal to the voltage impulses U100. The voltage impulsesat winding 64 therefore charge via the diode 113 the capacitor 6 to adirect voltage: U6=Um100−E.

In this way, energy that is collected in the windings 61 and 62 isconverted to energy in the capacitor 6: Wu=(×U6²*C6)/2=Wi, where ΔU6 arethe voltage impulses at the capacitor, produced by capacitativedischarge when no pulses Um are present, and C6 is the capacitance ofthe capacitor 6.

The direct voltage U108 feeds the generator 71, which is activated andcreates voltage rectangular pulses on the gate of the field effecttransistor 72 with a frequency of approximately 40 kHz. These impulsesopen and-close the transistor 72. Impulses with double amplitudeU103=2U6 are created on its drain output and on the winding 65. Thisequality is explained by the winding 66 of the second transformer havingthe same number of turns as the winding 65 and being connected to thewinding 65, and in this way creating impulses U97 with the oppositepolarity, but, due to the diode 97, the value of voltage at the winding66 lies between 0 and −U₁. This limits the amplitudes of the voltageimpulses in the windings 65-68.

When the diode 97 is open, capacitor 6 charges with the aid of thereturn current with all of the excess energy in the windings of thesecond transformer, which leads to a significant saving effect for thecomplete device.

The value of the voltage U6 depends on the condition of the luminescentlamp 73, of the type Polylux XL. During the instant of starting when thelamp does. not give a light and the current through it is equal to zero,the winding 65 acts with no load, the energy in the capacitor 6 is notconsumed and the voltage U6 will be equal to 600 V. This value islimited by the incorporation into the circuit of the zener diode 46. Theimpulse. amplitude at the drain output of the field effect transistor 72and to the common wire, respectively, does not exceed 1200 V, which islower that the value of the breakthrough voltage of the field effecttransistor 72, which is 1500 V. Thus the amplitude of the alternatingvoltage impulses at the winding 65 will be 600 V since the number ofturns in the coil 69 is half that of the number of turns in the winding65, and alternating voltage impulses with an amplitude of 900 V arecreated at the contact 103. The luminescent lamp 73, which is connectedto the contacts 102 and 104, is ignited by such a voltage, even withoutany warn-up circuits. The current through the lamp increases, thecapacitor 6 is rapidly discharged, and the voltage U6 decreases to thevalue 100 V. In this way, an alternating impulse voltage is createdbetween the contacts 102 and 104 with an amplitude of 150 V, which isequal to the operating voltage of the lamp. The alternating amplitudesof the lamp are symmetrical, which is why the lamp does not becomeextinguished at one of its ends.

The light of the lamp depends on the current that passes through it andthis current in turn depends on the energy Wi that is emitted by thewindings 61 and 62. This energy depends on the maximum current Im in thetransistor 50. This current arrives at the resistor 19 that has aresistance of 1 Ω, whereby a triangle-shaped voltage that depends onconductance is created. This voltage arrives at the potentiometer 35 andpasses from its regulator at a reduced scale to the base of thetransistor 52. The transistor opens when the base voltage exceeds 0.6 Vand begins to allow all the current from the resistor 16 to passthrough. The base current in the power transistor 50 will become 0, theincrease in current in the power transistor 50 ceases and it is switchedoff. The value of the current Im, can be changed within wide limits byregulation of the regulator of the potentiometer 35, and the intensityof illumination of the lamp 73 can be changed as a result of this. Theintensity of illumination at the lamp is stable such that the current inthe power transistor 50 can be regulated independently of itsproperties. The limit of regulation of the intensity of illuminationfrom a nominal value to lower values and changes in the power consumedby the device are ensured to more that 20 dB.

Feedback from the resistor 19 via the transistor 52 to the base of thepower transistor 50 also functions as a current-limiter for thetransistor 50. If the current in the transistor 50 starts to increase inan uncontrolled manner for any reason, in particular when the networksupply current is switched on, or if the lamp 73 is broken, the currentwill be limited by this circuit at the level that depends on the stateof the position of the regulator of the potentiometer 35 and thetransistor 50 retains its ability to function.

The device according to FIG. 1 b can function with two luminescent lamps74, 75 (low-pressure lamps of the sodium type SOX E) connected in serialbetween the contacts 104 and 105. In this way, as has already beenmentioned, the voltages at the contacts are equal in amplitude and ofopposite phase, which is why the difference between the two voltagesduring start-up is 1800 V, which leads to a rapid ignition of the lamps,and during combustion of gas the alternating voltage at the lamps has anamplitude of 300 V. The alternating current is symmetrical and the lampsare evenly illuminated along their complete length.

The device according to FIG. 1 c can function with four luminescentlamps 76-79 connected in series between the contacts 106 and 107. Sincethe number of turns in the windings 69, 70 when taken together is twicethat of the number of turns in the winding 65, and the relationships inthe windings 68, 67, 66 are the same, an alternating voltage is createdduring start-up at the contact 106 with an amplitude of 1800 V and avoltage of similar amplitude with opposite phase at the contact 107.Thus the voltage in the lamps has a magnitude of 3600 V, which leads torapid ignition of the lamps. During the combustion period an alternatingvoltage is present in the lamps with an amplitude of 600 V.

It is not specified for the known system according to U.S. Pat. No.4,005, 335 how large the consumed power is when two lamps are connected.It is, therefore, impossible to compare the device according to theinvention with this known system from the point of view of energysaving. However, it is possible to compare the present system with thetraditional circuit for a luminescent lamp of 40 Wh connected via achoke coil to an alternating current network.

The traditional circuit consumes 57 Wh. The present invention with onelamp and with the same intensity of illumination as the traditionalcircuit consumes 35 Wh. The device consumes 70 Wh when two lamps areused, 140 Wh when four lamps are used. If one calculates the saving forone lamp, a saving of energy of an average of 32% is obtained.

High-pressure mercury lamps of the type Kolorflux with a higher powercan be connected to the system instead of the low-pressure fluorescentlamps according to FIGS. 1 a, 1 b and 1 c. The difference will be thatthe Kolorflux lamps have a lower ignition voltage and that the voltageU6 will be significantly lower when current is connected than itsmaximum value of 600 V.

Lamps of the Kolorflux type, which are used for street lighting, can beconnected according to FIG. 1 d. The lamp is fed with direct voltage,something that is important for external illumination lamps in order toavoid the creation of electromagnetic disturbances with a frequency of40 Hz along the streets. In this case the voltage impulses from thewinding 61 will arrive at the capacitor 7 via the diode 43 and charge itup to the voltage:U7=(Um1−E)/2≈300 V.

This direct voltage ignites the lamp 80, the voltage in the lampsubsequently decreases to 160 V and the voltage impulses at thecollector of the transistor 50 become 600 V. In this case the part ofthe circuit containing the winding 64, the diode 113, the capacitor 6,the generator 71, the field effect transistor 72, the second transformerT2 with the windings 65-70 and the diode 97 is not needed.

The system can function according to FIG. 1 e with high-pressure sodiumlamps of the Lucalox type, or with a metal halogen lamp of the typeKolorarc, Multi-Vapour or Sportlight, that have a high ignition voltageof approximately 4 kV and a low combustion voltage of approximately 90V. In this case, voltage impulses Um1=1300 V are to be created at thecollector of the transistor 50. The zener diode 46 must have astabilisation voltage of 12.6 V for this. Thus it is appropriate thatthe number of turns in the winding 63 is twice the number of turns inthe windings 61 and 62 taken together. Voltage impulses Um1 charge thecapacitor 8 and the contact 98 to a positive voltage U8=Um1−E=1020 V viathe diode 44. When the transistor 50 is open the capacitor 9 is chargedvia the diode 45 to a voltage U9=U8+3*E=1860 V. When the transistor 50is closed, the voltage at the contact 101 reaches a value ofU101=(Um1−E)*3+E=3340 V.

In this case a voltage U81=U101+UC9 5200 V is created in the lamp 81.This voltage ignites the lamp 81 at the first attempt, (both when coldand when warm). A direct voltage that is approximately 90 V will arriveat the lamp after ignition from the capacitor 8 via the diode 45. Thecapacitor 9 influences the action of the circuit to a small degree sinceits capacitance is very much smaller than the capacitance of thecapacitor 8. The amplitude of the voltage impulses at the collector ofthe transistor 50 is thus Um2 E+90 V=370 V. The capacitor 8 is regularlycharged via the diode 44 by this impulse.

Circuits are arranged in the system for the control of the intensity ofillumination for lamps of all types. The phototransistor 56 is used,placed where there is external illumination and where the light from thelamp does not reach. In the absence of external illumination there is nocurrent in the phototransistor, the transistor 51 is closed and does notinfluence the action of the system, the lamp gives a light within itsnominal region. If external illumination is present, the current passesthrough the phototransistor 56 and arrives at the base of the transistor51, the transistor 51 opens and reduces the base currents in thetransistor 50, and this leads to a reduction of the current Im and anequivalent reduction of the intensity of illumination of the lamp. Ifthe external illumination is bright, the lamp does not give light atall. The lamp is reignited if the external illumination disappears. Theaction of the lamp can be automatically regulated in this way such thatthe lamp does not give a light during the daytime, gives a light at areduced power during dusk and gives a light in its nominal region atnighttime. A great deal of energy is saved due to such a rationalillumination.

A phototransistor 57 is mounted on the surface of the lamp according toFIG. 1 f. The lamp will be caused to give a stable light in this way. Inthis case, the current in the phototransistor depends only on the lightof the lamp, and the voltage at its collector will be inverselyproportional to the intensity of illumination of the lamp. This voltageis applied to the inverse input of the amplifier 82. Part of the voltagefrom the zener diode 47 is applies to the second input of the amplifier82. The level of this voltage depends on the potentiometer 36. Theoutput voltage from the amplifier 82 is applied to the base oftransistor 51. If the intensity of illumination of the lamp increases byan unreasonable amount, the voltage at the collector of thephototransistor 57 will decrease, the voltage at the output of theamplifier increases, the base current in the transistor 51 increases andit opens further and decreases the intensity of illumination of thelamp. The circuit functions such that the voltages at the inputs to theamplifier are always equal and stable. Thus the light emitted by thelamp is also stable. The intensity of the light is regulated with theaid of the potentiometer 36 by changing the voltage across the dividerwith the resistors 22 and 36, the voltage at the collector of thephototransistor 57 is changed and the intensity of illumination of thelamp is changed. Thus the intensity of illumination of the lamp does notdepend on oscillations in the electrical supply network or of the age ofthe lamp, and in this way the lifetime of the lamp is increased.Considerably more energy is also saved since the intensity ofillumination of the lamp does not increase above normal even if thevoltage in the electrical supply network increases. The energy thatwould be needed for such an increase is not consumed and this does notshorten the lifetime of the lamp, which may otherwise happen.

A thermoresistor 38 is mounted according to FIG. 1 g onto the powertransistor 50 or the field effect transistor 72. If the particulartransistor becomes overheated, the magnitude of the thermoresistancedecreases very dramatically, the current that passes, through thethermoresistor increases and arrives at the base of the transistor 51,:which opens and decreases the value of the current Im. In this case, theintensity of illumination of the lamp decreases, the energy consumeddecreases, heating of the relevant transistor decreases, and thetransistor is protected from heat breakdown.

The system can also handle automatic ignition and/or extinguishing of alamp depending on the presence of people close to the lamp. This isnecessary, for example, for the illumination of indoor staircases,corridors in hotels and entrances to houses and garages.

A microphone 87 is connected according to FIG. 1 h to the base of atransistor 53 via an amplifier 83 and an amplitude detector 88. If aperson passes by, the microphone 87 records the noise of steps, theamplifier 83 amplifies the signals and converts them to voltage impulsesat the output of the amplitude detector 88. The pulses are integrated inthe capacitor 10 and direct voltage arrives at the base of thetransistor 53, the voltage at the collector of which decreases to 0. Thetransistor 53 is closed and the lamp starts to light. After the personhas passed by, the capacitor 10 remains charged for a period and thelamp continues to light. The capacitor 10 subsequently discharges, thetransistor 53 closes and the transistor 51 opens with the current thatpasses via the resistor 24, and the lamp is extinguished.

A Schmitt trigger is activated according to FIG. 1 k as a generator at ahigh frequency, due to the feedback in the form of the resistor 25 andthe capacitor 11. The frequency of the signal of the generator dependson the magnitude of the capacitance in the capacitor 11. If a person ispresent moving in the vicinity, the capacitance contact 91, which isplaced externally to the system, alters the capacitance relative to thecommon wire. The frequency of the generator is changed as a result ofthe person's movements. The frequency detector 93 converts the changesin frequency to change in the output voltage, which is amplified by theamplifier 84 and emerges at the output of the amplitude detector 89 asconstant pulses. The capacitor 12 integrates these pulses and ignitesthe lamp via the transistor 54. After the passage of a person, thefrequency of the generator becomes constant, a direct voltage is appliedto the output of the frequency detector, the signal decreases to 0 atthe output of the amplitude detector and the lamp becomes extinguishedwithin a certain period.

An infrared power light emitting diode 49 illuminates according to FIG.1 l the surrounding space. The light is reflected by objects and arrivesat the input to an infrared phototransistor 58. If a person moves in thevicinity, the reflected light is changed in co-ordination with themovements of the person. The current in the phototransistor 58 ischanged, the alternating signal at the input to amplifier 85 isstrengthened and converted to pulses at the output of the amplitudedetector 90, the capacitor 13 is charged, opens transistor 55 andignites the lamp. After the person has passed, the reflected light fromthe diode 49 will become constant, the voltage at the output of theamplitude detector decreases to 0, and the lamp is extinguished.

An accumulator 94 is charged according to FIG. 1 m via the diode 42 anda timer 95, that is a clock with an annual calendar in which informationconcerning the start and end of all nights throughout the year isavailable. Thus the timer sends a 0-signal to the base of the resistor51 every night in order to ignite the lamp. The timer creates a constantsignal at its output that opens the transistor 51 during each day, andthe lamp does not give a light.

Use of the system according to FIGS. 1 h, 1 k and 1 l allows thepossibility of saving energy to a degree exceeding 50%, since the lampsare ignited only when persons are present and are in practice alwaysextinguished during the night.

It is no longer necessary to use mechanical switches, which extends thelifetime of the lamps and increases the level of comfort for the users.Use of the device with the phototransistor 56 and according to FIG. 1 mallows the possibility of connecting the lamps for outdoor illuminationto an ordinary electrical supply network that is never switched off.

The need of laying down a special supply network disappears, which leadsto considerable savings.

It must be pointed out that all systems automatically connect the powertransistor 50 via the transistor 51 in order to prevent their outputcurrent from exceeding:Ia≦Im/(β50*β51);≈10⁻³-Im

This current is small since little energy is consumed and low-powersensors can be used. The use of phototransistors ensures a greatersensitivity for the emitted light than the use of photoresistors andphotodiodes.

The system according to FIG. 1 n allows the possibility of stabilisingthe power consumed from the supply network during changes in :voltagewithin 220 V ±60 V. The power that is consumed by the system passes to alarge degree through the power transistor 50. The value of this poweris:T₀P=E(1/To)*∫I ₅₀ dt=E*I _(50cp),where T₀ is the period of oscillations of impulses, at the collector ofthe power transistor 50;

-   I₅₀ is the current in power transistor 50; and-   I_(50cp) is the mean current in the power transistor 50.

The current in the power transistor 50 arrives in the form of voltage atthe resistor 19 and has a triangle form. The resistor 34 and thecapacitor 14 integrate this signal and a voltage that is proportional toI_(50cp) is applied to the input of the multiplier 96. The voltage U108at the cathode of the diode 42 is proportional to the voltage E or thevoltage in the supply network. This is why a voltage is applied on theoutput of the multiplier 96 that is proportional to the power consumed.This voltage is compared in the amplifier 86 with the stable voltagethat is applied with the aid of the potentiometer 37 onto the secondinput of the amplifier. These voltages are equal.

The output signal from the amplifier 86 controls the transistor 52 andregulates the intensity of illumination of the lamp and, consequently,regulates the level of the power consumed. The regulation of thepotentiometer 37 changes the voltage at this resistor and this meansthat the level of the power consumed and therefore the intensity ofillumination of the lamp can be changed. The intensity of illuminationof the lamp will be stable during changes in voltage in the supplynetwork within ±30%. Hence the system will be an excellent source foralternating current and direct current that maintain a constant power atthe lamp that is determined by the potentiometer 37, independent ofoscillations in the supply network and the age of the lamp.

Such a property of the device is particularly important for sodiumvapour lamps of high-pressure type, such as Lucalox. These lamps arevery sensitive to overconsumption of the power consumed. When thevoltage in the supply network increases, the lamp becomes overheated;consumption of mercury increases and the lamp looses illuminationcapacity an is rapidly destroyed. This property is present if the lampis supplied according to the traditional circuit via a choke coil.Furthermore, as the lamp becomes older, its internal resistanceincreases, the current that passes through the lamp decreases and thechoke coil connection does not ensure the stable functioning of thelamp, such that the luminous lamp, becomes extinguished, cools, isre-ignited, and so on. Many ignition and extinguishing attempts destroythe electrodes of the lamp and the lamp becomes black.

The device according to the invention can rapidly, at the first attempt,ignite the lamp and maintain undestroyed electrodes. The stable powerconsumption of the lamp reduces its overheating, reduces the consumptionof mercury and as a consequence of this extends the lifetime of thelamp. The device ensures the stable illumination effect of the lamp whenthe internal resistance of the lamp rises as time passes, the voltagedrop across the lamp consequently increases, which only improves thefunction of the device and eliminates flickering of the lamp, somethingthat also extends the lifetime of the lamp. There is no need to installan expensive mercury dosage unit in the lamp.

If the lamps are supplied via a choke coil, they have twice thedifference in the intensity of illumination. When the device accordingto the invention is used, the lamps consume a constant power and all thelamps used have the same level of the intensity of illumination as aconsequence of this.

To summarise: the device according to the invention has many advantagesover known systems. It is namely possible to simultaneously connect one,two or four luminescent lamps and to ensure their even and stableintensity of illumination along the complete length of the lamps. It ispossible simultaneously to connect mercury lamps with high pressure in aquantity from one to four, one or two sodium vapour lamps ofhigh-pressure type or of low-pressure type, or one or two metal halogenlamps. Protection for the power transistor is ensured not only againstvoltage but also against current and against overheating, something thatsignificantly increases the safety of the system. The scale for themanual regulation of the intensity of illumination of the lamps isextended by a factor of five, the stability of illumination of the lampsfollowing the regulation process is increased.

A high stability of the intensity of illumination of the lamps when thevoltage in the supply network changes within ±30% is achieved, and thelamps maintain a stable emission of light even if they become older. Astabilisation of the power consumed by the lamps is achieved, somethingthat is particularly important when the network supply voltage isincreased. As a result of this, an increase in the lifetimes of thelamps is ensured, that is, the lamps do not burn out as. a result ofoverloading.

Automatic ignition and extinguishing of street lamps is ensured by threedifferent methods depending on the external illumination or the time ofday, something that saves energy up to a level of 20%.

Automatic ignition and extinguishing of security lamps is ensured bythree different methods depending on the presence of persons, somethingthat saves energy up to a level of 50%. The large saving arises due tothe fact that it is not necessary to build up a special supply networkthat can be disconnected for street lamps that have their owndisconnection circuits. The device for which a patent is applied savesan average of up to 30% electrical energy for street lamps compared withan equivalent solution using choke coils.

Use of the device for which a patent is applied for the supply ofhigh-voltage lamps of sodium vapour type or of metal halogen typeensures a rapid ignition of the lamps with a high direct voltage, andoperation with a low direct voltage within the nominal region ofoperation, something that ensures that there are no disturbances in theelectromagnetic field that contaminate the environment.

Different models of the system assembled according to the systemaccording to the invention function well for different types of lampwith powers from 40 to 250 Wh. There are, however, no difficulties inincreasing the power of the lamps used up to 1 kWh.

The saving of electricity when using this device also arises due to thefact that all lamps have been made in practice for a supply network of220±10% V. The lamps are to function within the nominal region at thelowest value of the supply voltage, 198 V. At a voltage of 220 V andhigher in the network, the lamps function with an excess over thenominal intensity of illumination and consume more electrical energy(approximately 10-20%). The present system stabilises the power consumedwith a precision of 1% when there are changes in the supply network of220 V±30% V. If the device is adjusted such that the intensity ofillumination is equivalent to the intensity of the strength ofillumination of the lamps that are supplied by conventional systems at avoltage of 198 V, the saving can be up to 20% at the same intensity ofillumination.

Many elements in the system, including the elements that functionautomatically, can be made as a microcircuit which ensures a highsecurity of the device with small dimensions.

The present system can be used for the illumination of premises, streetsand in order to create emergency lighting in locations where such arenecessary. Its use ensures new variations of the use of illuminationequipment, increases comfort when in use, increases safety of the lampsthat are used, extends the lifetimes of the lamps, ensures a significantsaving with respect to electricity consumption and can give a majoreconomic gain.

References

-   1. U.S. Pat. No. 5,130,609, filed 26 Jan. 1990, published 17 Jul.    1992.-   2. Patent UK, application number 2 047 486, filed 12 Apr. 1979,    published 26 Nov. 1980.-   3. U.S. Pat. No. 4,005,335, filed 15 Jul. 1975, published 25 Jan.    1977.

1. A energy saving system for the ignition, operation and extinguishingof connected gas-discharge lamps which system is connected to thealternating current supply network via a rectifier (1), a capacitor (2),a power transistor (50) and a first transformer (T1) with at least fourwindings (59-63), which said units are not only part of an ignitioncircuit for the rapid ignition of the lamps with a high direct voltage,but also part of an oscillator circuit for operation of the lamps at alower voltage and part of a direct voltage circuit with a lower voltagefor the operation of the components that are included in the system,characterised in that the system furthermore comprises means (64, 113,6, T2, 71, 72, 97), comprising a second transformer (T2) with at leastsix windings, for the connection and simultaneous ignition of 1-4luminescent lamps (73-79) or the equivalent, and with a pulse generator(71) and a field effect transistor (72) for the operation of the secondtransformer (T2), means (61, 43, 7) for the connection of ahigh-pressure mercury lamp (80) or the equivalent that is supplied withdirect current and that has a low ignition voltage and high power; andmeans (61, 62, 63, 44, 45, 8, 9) for the connection of a high-pressuresodium vapour lamp or metal halogen lamp (81) or the equivalent with anignition voltage of approximately 4 kV and low operational voltage,means (46) connected to the base of the power transistor (50), in orderto stabilise the emission of light from the lamp or lamps when thesupply networks voltage changes, means (59, 39, 3, 46, 19, 35, 52) tolimit the current and the voltage through the power transistor (50),whereby the electrodes of the lamp or lamps (73-81) are connected tooutputs (98-101) of the windings (61-63) of the first transformer (T1)or outputs (102-107) of windings (65-70) of the second transformer (T2)which windings are mutually connected and designed such that theycooperate in order to operate the relevant connected lamp with anegative current amplitude that has the same magnitude as the positivecurrent amplitude and to supply the relevant lamp or lamps with theignition and operational voltages required.
 2. The system according toclaim 1, characterised in that it comprises a phototransistor (56) orequivalent element in order to influence the current to the base of thepower transistor (50) depending on the incident light and in this wayautomatically control the ignition, operation and extinguishing of therelevant lamp or lamps.
 3. The system according to any one of claim 1,whereby the inputs of the rectifier (1) in the system are connected tothe alternating current supply network, and the outputs of the rectifier(1) are connected to electrodes of the capacitor (2), whereby thepositive output of the rectifier is connected to a contact (98) of afirst winding (61) of the first transformer (T1), and is connected via afirst resistor (15) to electrodes of second (16) and third (17)resistors and to the electrode of a second capacitor (4), which istogether with the second electrode connected to the anode of a firstdiode (40) and to the contact of the second winding (60) of thetransformer (T1), whereby the cathode of the first diode (40) isconnected to the second electrode of the second resistor (16), andwhereby a second contact of the second winding (60) of the transformer(T1) is connected to the negative output of the rectifier, to contactson third (59) and fourth (64) windings of the transformer (T1), to anelectrode of a potentiometer (35), to an electrode of a third capacitor(6), to an electrode of a fourth resistor (19) and via a fourthcapacitor (3) to the anode of a zener diode (46), characterised in thatthe system comprises fifth (62) and sixth (63) windings of thetransformer (T1), a phototransistor (56), a pulse generator (71), afield effect transistor (72), together with a second transformer (T2)with six windings (65-70), whereby the second resistor (16) is connectedto the base of the power transistor (50), to the cathode of the zenerdiode (46), to the collectors of first and second transistors (51, 52);and that the second electrode of the third resistor (17) is connected tothe anode of a second diode (41) whereby its cathode is connected to theanode of the first diode (40), to the second contact of the secondwinding (60) of the first transformer (T1), to the anode of a thirddiode (42), the cathode of which is connected to the electrode of afifth capacitor (5), to the feed output of the generator (71), to thecollector of the phototransistor (56), the emitter of which is connectedto the base of the first transistor (51) and via a fifth resistor (18)to the emitters of the first and second transistors (51, 52), to thesecond electrode of the fifth capacitor (5), to a common output of thegenerator (71), to the source of the field effect transistor (72), tothe anode of a fourth diode (97) and to the negative output of therectifier (1), and that the second contact of the third winding (59) ofthe first transformer (T1) is connected to the cathode of a fifth diode(39) whereby its anode is connected to the anode of the zener diode(46); and that the emitter of the power transistor (50) is connected tothe second electrodes of the fourth resistor (19) and the potentiometer(35), the regulator of which is connected to the base of the secondtransistor (52), and that the output of the generator (71) is connectedto the gate of the field effect transistor (72), the drain of which isconnected via the first winding (65) of the second transformer (T2), tothe second electrode of the third capacitor (6), to the cathode of asixth diode (113), the anode of which is connected to the second contactof the fourth winding (64) of the first transformer (T1), the firstwinding (61) of which is connected with its second contact via a fifthwinding (62) to the contact of a sixth winding (63) and to the collectorof the power transistor (50); and that the second transformer (T2) isconnected with the contact of the second winding (66) to the cathode ofthe sixth diode (113), and the second contact of the second winding (66)is connected to the cathode of the fourth diode (97) and to third (67)and fourth (68) windings connected in series, and that the output of thefield effect transistor (72) is connected via the fifth winding (69) tothe contact of the sixth winding (70).
 4. The system according to claim3, characterised in that two lamps (74, 75) connected in series areconnected between a common contact (105) to third (67) and fourth (68)windings of the second transformer (T2) on the one side, and between acommon contact (104) to fifth (69) and sixth (70) windings of the secondtransformer (T2) on the other side.
 5. The system according to claim 3,characterised in that the second contact (107) of the fourth winding(68) of the second transformer (T2) is connected via four lamps (76-79)connected in series to the second contact (106) of the sixth winding(70) of the second transformer.
 6. The system according to claim 3,characterised in that the common contact (99) of first (61) and fifth(62) windings of the first transformer (T1) is connected to the anode ofa diode (43) and that its cathode is connected via capacitor (7) andlamp (80) connected in parallel to the positive output (98) of therectifier.
 7. The system according to claim 3, characterised in that thecollector (100) of the power transistor (50) is connected to the anodeof a diode (44), the cathode of which is connected via a capacitor (8)to the positive output (98) of the rectifier and via a lamp (81) to thecathode of a second diode (45) and via a capacitor (9) to the secondcontact (101) of the sixth winding (63) of the first transformer (T1)and that the anode of the last-mentioned diode (45) is connected to thecathode of the first-mentioned diode (44).
 8. The system according toclaim 3, characterised in that the emitter (109) of a phototransistor(57) is connected to the anode of a second zener diode (47), to theelectrode and the regulator of a potentiometer (36), to the commonoutput of an amplifier (82), and to the negative output (109) of therectifier, and that the collector of the phototransistor (57) isconnected to the inverse input of the amplifier (82) and via a resistor(20) to the electrode of a further resistor (21), to the supply contactof the amplifier (82) and to the cathode (108) of the third diode, andthat the direct input of the amplifier (82) is connected to the secondelectrode of the potentiometer (36) and to the electrode of a resistor(22), the second electrode of which is connected to the cathode of thesecond zener diode (47) and to the second electrode of the furtherresistor (21), and that the output (110) of the amplifier (82) isconnected to the base of the first transistor (51).
 9. The systemaccording to claim 3, characterised in that the base (110) of the firsttransistor (51) is connected via a thermoresistor (38) to the cathode(108) of the third diode (42).
 10. The system according to claim 3,characterised in that the negative output of the rectifier (109) isconnected to common outputs of a microphone (87), an amplifier (83), anamplitude detector (88), to the electrode of a capacitor (10) and withthe emitter of a third transistor (53), whereby the output of themicrophone (87) is connected to the input of the amplifier (83), theoutput of which is connected to the input of the amplitude detector(88), the output of which is connected to the second electrode of thecapacitor (10) and with the base of the third transistor (53), thecollector (110) of which is connected to the base of the firsttransistor (51) and via a resistor (24) to the supply contacts of theamplitude detector (88) and the amplifier (83) and to the cathode (108)of the third diode (42).
 11. The system according to claim 3,characterised in that the negative output of the rectifier (109) isconnected to common outputs of a Schmitt trigger (92), a frequencydetector (93), an amplifier (84), an amplitude detector (89), to theelectrode of a capacitor (11), to the electrode of a further capacitor(12), to the emitter of a third transistor (54), whereby a capacitanceelectrode (91) is connected to the input of the Schmitt trigger (92) andvia a resistor (25) to the output of the Schmitt trigger (92) and to theinput of the frequency detector (89), the output of which is connectedto the input of the amplifier (84), the output of which is connected tothe amplitude detector (89), the output of which is, in turn, connectedto the second electrode of the additional capacitor (12) and to the baseof the third transistor (54), the collector of which is connected to thebase (110) of the first transistor (51) and via a resistor (26) tosupply outputs (109) of the amplitude detector, the amplifier, thefrequency detector, the Schmitt trigger and the cathode of the thirddiode (42).
 12. The system according to claim 3, characterised in thatthe negative output of the rectifier (109) is connected to commonoutputs of an amplifier (85) and an amplitude detector (90), to thecathode of a photodiode (49), to the electrode of a capacitor (13), tothe emitter of a transistor (55) and to the emitter of a phototransistor(58), the collector of which is connected to the electrode of a furtherresistor (28) and to the input of the amplifier (85), the output ofwhich is connected to the input of the amplitude detector (90), theoutput of which is connected to the second electrode of the capacitor(13) and to the base of the transistor (55), the collector of which isconnected to the base (110) of the first transistor (51) and via aresistor (29) to supply outputs (108) of the amplitude detector (90) andthe amplifier (85), to the second electrode of the additional resistor(28), to the cathode of the third diode (42) and via a resistor (27) tothe anode of the light diode (49).
 13. The system according to claim 3,characterised in that the negative output of the rectifier (109) isconnected to a common output of a timer (95) and to the negativeelectrode of an accumulator (94), whereby the cathode (108) of the thirddiode (42) is connected to the positive electrode of the accumulator(94) and to the supply output of the timer (95), the output of which isconnected to the base (110) of the first transistor.
 14. The systemaccording to claim 3, characterised in that the regulator of apotentiometer (37) is connected to the anode of a second zener diode(48), to negative supply outputs of an amplifier (86) and a multiplier(96), to the negative output (109) of the rectifier and to one electrodeof a capacitor (14), the second electrode of which is connected to theinput of the multiplier (96) and via a resistor (34) to the emitter(112) of the power transistor (50), whereby the second input of themultiplier (96) is connected via a resistor (32) with positive supplyoutputs of the multiplier (96) and the amplifier (86), with the output(108) of the cathode of the third diode (42), and via a resistor (31)both to the cathode of the second zener diode (48) and via a resistor(30) to the inverse input of the amplifier (86), the second input ofwhich is connected to the output of the multiplier (96), and whereby theoutput (111) of the amplifier is connected to the base of the secondtransistor (52).
 15. The system according to any one of claim 2, wherebythe inputs of the rectifier (1) in the system are connected to thealternating current supply network, and the outputs of the rectifier (1)are connected to electrodes of the capacitor (2), whereby the positiveoutput of the rectifier is connected to a contact (98) of a firstwinding (61) of the first transformer (T1), and is connected via a firstresistor (15) to electrodes of second (16) and third (17) resistors andto the electrode of a second capacitor (4), which is together with thesecond electrode connected to the anode of a first diode (40) and to thecontact of the second winding (60) of the transformer (T1), whereby thecathode of the first diode (40) is connected to the second electrode ofthe second resistor (16), and whereby a second contact of the secondwinding (60) of the transformer (T1) is connected to the negative outputof the rectifier, to contacts on third (59) and fourth (64) windings ofthe transformer (T1), to an electrode of a potentiometer (35), to anelectrode of a third capacitor (6), to an electrode of a fourth resistor(19) and via a fourth capacitor (3) to the anode of a zener diode (46),characterised in that the system comprises fifth (62) and sixth (63)windings of the transformer (T1), a phototransistor (56), a pulsegenerator (71), a field effect transistor (72), together with a secondtransformer (12) with six windings (65-70), whereby the second resistor(16) is connected to the base of the power transistor (50), to thecathode of the zener diode (46), to the collectors of first and secondtransistors (51, 52); and that the second electrode of the thirdresistor (17) is connected to the anode of a second diode (41) wherebyits cathode is connected to the anode of the first diode (40), to thesecond contact of the second winding (60) of the first transformer (T1),to the anode of a third diode (42), the cathode of which is connected tothe electrode of a fifth capacitor (5), to the feed output of thegenerator (71), to the collector of the phototransistor (56), theemitter of which is connected to the base of the first transistor (51)and via a fifth resistor (18) to the emitters of the first and secondtransistors (51, 52), to the second electrode of the fifth capacitor(5), to a common output of the generator (71), to the source of thefield effect transistor (72), to the anode of a fourth diode (97) and tothe negative output of the rectifier (1), and that the second contact ofthe third winding (59) of the first transformer (T1) is connected to thecathode of a fifth diode (39) whereby its anode is connected to theanode of the zener diode (46); and that the emitter of the powertransistor (50) is connected to the second electrodes of the fourthresistor (19) and the potentiometer (35), the regulator of which isconnected to the base of the second transistor (52), and that the outputof the generator (71) is connected to the gate of the field effecttransistor (72), the drain of which is connected via the first winding(65) of the second transformer (T2), to the second electrode of thethird capacitor (6), to the cathode of a sixth diode (113), the anode ofwhich is connected to the second contact of the fourth winding (64) ofthe first transformer (T1), the first winding (61) of which is connectedwith its second contact via a fifth winding (62) to the contact of asixth winding (63) and to the collector of the power transistor (50);and that the second transformer (T2) is connected with the contact ofthe second winding (66) to the cathode of the sixth diode (113), and thesecond contact of the second winding (66) is connected to the cathode ofthe fourth diode (97) and to third (67) and fourth (68) windingsconnected in series, and that the output of the field effect transistor(72) is connected via the fifth winding (69) to the contact of the sixthwinding (70).